Confocal microscopy for healthy and pathological nail

Advances in image-based diagnosis of nail disorders

This paper provides a comprehensive overview of image-based techniques, particularly focusing on their applications and advancements in the context of nail disorders. Nowadays, high-resolution digital cameras and dermoscopes enable dermatologists to capture detailed images of nail abnormalities, facilitating early diagnosis and meticulous tracking of disease progression. Onychoscopy is now a routine technique with well-known criteria for the diagnosis, but recent developments allow us to visualize certain diseases better. Imaging modalities like high-frequency ultrasound, magnetic resonance imaging, optical coherence tomography and confocal microscopy are being increasingly adopted for their superior diagnostic capabilities. These techniques are described in their technology, scanning protocols, normal findings, advantages and limitations. Moreover, the integration of technology in patient education has fostered a more informed patient population, capable of actively participating in their disease monitoring and treatment regimens. Proper training, validation, regulation and ethical considerations are, however, essential when integrating technology into healthcare practices. Imaging technologies that present the potential to add critical anatomical information to clinical diagnoses within reasonable costs and are available worldwide are the ones that will probably be used the most.

Line-field confocal optical coherence tomography, a novel non-invasive tool for the diagnosis of onychomycosis

BACKGROUND AND OBJECTIVES

Onychomycosis is common and important to distinguish from other nail diseases. Rapid and accurate diagnosis is necessary for optimal patient treatment and outcome. Non-invasive diagnostic tools have increasing potential for nail diseases including onychomycosis. This study evaluated line-field confocal optical coherence tomography (LC-OCT) as a rapid non-invasive tool for diagnosing onychomycosis as compared to confocal laser scanning microscopy (CLSM), optical coherence tomography (OCT), and conventional methods.

PATIENTS AND METHODS

In this prospective study 86 patients with clinically suspected onychomycosis and 14 controls were examined using LC-OCT, OCT, and CLSM. KOH-preparation, fungal culture, PCR, and histopathology were used as comparative conventional methods.

RESULTS

LC-OCT had the highest sensitivity and negative predictive value of all methods used, closely followed by PCR and OCT. Specificity and positive predictive value of LC-OCT were as high as with CLSM, while OCT scored much lower. The gold standard technique, fungal culture, showed the lowest sensitivity and negative predictive value. Only PCR and culture allowed species differentiation.

CONCLUSIONS

LC-OCT enables quick and non-invasive detection of onychomycosis, with advantages over CLSM and OCT, and similar diagnostic accuracy to PCR but lacking species differentiation. For accurate nail examination, LC-OCT requires well-trained and experienced operators.

Nail psoriasis and nail lichen planus: Updates on diagnosis and management

BACKGROUND

Inflammatory diseases of the nail, including nail psoriasis and nail lichen planus, are associated with significant disease burden and have a negative impact on quality of life. Diagnosis is often delayed, especially when patients present without cutaneous findings. Therefore, recognizing clinical signs and symptoms of inflammatory nail diseases, and initiating timely and appropriate treatment, is of utmost importance.

OBJECTIVE

We review recent studies on diagnostic techniques, discuss severity grading and scoring systems, and describe consensus treatment recommendations for nail psoriasis and nail lichen planus.

METHODS

An updated literature review was performed using the PubMed database on studies assessing diagnostic techniques or treatment modalities for nail psoriasis and nail lichen planus.

RESULTS

Recent studies on diagnostic techniques for inflammatory nail disease have focused on use of dermoscopy, capillaroscopy, and ultrasound modalities. Treatment of these conditions is dichotomized into involvement of few (≤3) or many (>3) nails. Recent psoriatic therapeutics studied for nail outcomes include brodalumab, tildrakizumab, risankizumab, deucravacitinib, and bimekizumab, while emerging treatments for nail lichen planus include JAK inhibitors and intralesional platelet rich plasma injections.

CONCLUSIONS

We emphasize the need for increased awareness and expanded management strategies for inflammatory nail diseases to improve patient outcomes.

Konfokale Line-Field optische Kohärenztomographie, ein innovatives nichtinvasives Instrument zur Diagnose der Onychomykose: Line-field confocal optical coherence tomography, a novel non-invasive tool for the diagnosis of onychomycosis

Hintergrund und Ziele

Onychomykose ist weit verbreitet und sollte von anderen Nagelerkrankungen unterschieden werden. Eine rasche und genaue Diagnostik ist für die optimale Behandlung des Patienten und ein bestmögliches Ergebnis erforderlich. Nichtinvasive Techniken haben ein wachsendes Potenzial bei der Diagnose von Nagelerkrankungen, einschließlich Onychomykose. In dieser Studie wurde die konfokale Line‐Field optische Kohärenztomographie (LC‐OCT) als schnelle nichtinvasive Methode zur Diagnose von Onychomykose im Vergleich zur konfokalen Laserscanmikroskopie (KLM), optischen Kohärenztomographie (OCT) und konventionellen Methoden bewertet.

Patienten und Methodik

In dieser prospektiven Studie wurden 86 Patienten mit klinischem Verdacht auf Onychomykose und 14 Kontrollen mittels LC‐OCT, OCT und KLM untersucht. KOH‐Präparation, Pilzkultur, PCR und Histopathologie wurden als vergleichende konventionelle Methoden eingesetzt.

Ergebnisse

LC‐OCT hatte die höchste Sensitivität und den höchsten negativen Vorhersagewert aller verwendeten Methoden, dicht gefolgt von PCR und OCT. Die Spezifität und der positive Vorhersagewert der LC‐OCT waren genauso hoch wie bei der KLM, während OCT deutlich schlechter abschnitt. Das Goldstandardverfahren Pilzkultur zeigte die geringste Sensitivität und den niedrigsten negativen Vorhersagewert. Nur PCR und Kultur ermöglichten eine Differenzierung der Pilzspezies.

Schlussfolgerungen

LC‐OCT ermöglicht eine schnelle und nichtinvasive Diagnostik von Onychomykose, mit Vorteilen gegenüber KLM und OCT und ähnlicher diagnostischer Genauigkeit wie die PCR, aber ohne Differenzierung der Pilzarten. Für eine genaue Nageluntersuchung erfordert die LC‐OCT gut geschulte und erfahrene Anwender.

Novel Discoveries and Clinical Advancements for Treating Onychomycosis: A Mechanistic Insight

Onychomycosis continues to be the most challenging disease condition for pharmaceutical scientists to develop an effective drug delivery system. Treatment challenges lie in incomplete cure and high relapse rate. Present compilation provides cumulative information on pathophysiology, diagnostic techniques, and conventional treatment strategies to manage onychomycosis. Novel technologies developed for successful delivery of antifungal molecules are also discussed in brief. Multidirectional information offered by this article also unlocks the panoramic view of leading patented technologies and clinical trials. The obtained clinical landscape recommends the use of advanced technology driven approaches, as a promising way-out for treatment of onychomycosis. Collectively, present review warrants the application of novel technologies for the successful management of onychomycosis. This review will assist readers to envision a better understanding about the technologies available for combating onychomycosis. We also trust that these contributions address and certainly will encourage the design and development of nanocarriers-based delivery vehicles for effective management of onychomycosis.

Role of VivaScope 2500 ex vivo confocal microscopy in skin pathology: Advantages, limitations, and future prospects

BACKGROUND

Vivascope 2500 ex vivo confocal microscopy (EVCM) is an emerging optical imaging device that allows nuclear level resolution of freshly excised tissues. EVCM provides, rapid real-time pathological examination in many subspecialties of pathology including skin, prostate, breast, liver, etc. In contrast to traditional time-consuming frozen sectioning and histological analysis.

AIMS

To evaluate the current state of EVCM utilization.

MATERIALS AND METHODS

This study highlights the advantages, limitations, and prospects of EVCM in skin pathology.

RESULTS

Our findings demonstrate that EVCM is a promising adjunctive tool to assess margins in Mohs surgery and to provide rapid, accurate diagnosis of cutaneous tumors, infectious and inflammatory diseases.

CONCLUSION

EVCM is a revolutionary device that can be used as an adjunct to paraffin-fixed, hematoxylin and eosin-stained slides and frozen sectioning. Additional refinements are required before EVCM can be used as an alternative to frozen sectioning or traditional tissue processing.

Applications of Reflectance Confocal Microscopy in the Diagnosis of Fungal Infections: A Systematic Review

Cutaneous and adnexal fungal infections are typically diagnosed with potassium hydroxide (KOH) skin scrapings, fungal cultures, and Periodic acid-Schiff (PAS) biopsy staining. All three current methods of fungal diagnosis require sample processing and turnover time which leads to a delay in diagnosis. Reflectance confocal microscopy (RCM) is a non-invasive, in vivo skin imaging technology that provides real-time dermatologic diagnoses. We present an updated systematic review of the applications of RCM in diagnosing fungal infections in an effort to explore the utility of RCM as an adjunct clinical tool in detecting cutaneous and adnexal fungi We systematically searched the MEDLINE (via PubMed) for studies published from January 2000 to October 2022 that described the utility of RCM in the setting of fungal infections. Of the 25 studies that met the inclusion criteria, 202 patients were included. The following information on the application of RCM in the setting of fungal infections was extracted from each study, if reported: study type, year published, number of patients included, diagnosis/diagnostic methods, and RCM description. Concordant within all included studies, fungal infections presented on RCM as bright, linear, branching, filamentous structures at the level of stratum corneum. A limitation of this review is that 11 of 25 studies were case reports (n = 1). Larger scale studies should be conducted to explore the utility of RCM in diagnosing fungal infections and to enrich the RCM descriptions of specific fungal conditions.

Challenge of Nail Psoriasis: An Update Review

Nail psoriasis is a refractory disease that affects 50-79% skin psoriasis patients and up to 80% of patients with psoriatic arthritis (PsA). The pathogenesis of nail psoriasis is still not fully illuminated, although some peculiar inflammatory cytokines and chemokines seems to be the same as described in psoriatic skin lesions. Psoriatic nail involving matrix can cause pitting, leukonychia, red spots in lunula, and nail plate crumbling, while nail bed involvement can result in onycholysis, oil-drop discoloration, nail bed hyperkeratosis, and splinter hemorrhages. The common assessment methods of evaluating nail psoriasis includes Nail Psoriasis Severity Index (NAPSI), Nail Assessment in Psoriasis and Psoriatic Arthritis (NAPPA), Nail Psoriasis Quality of life 10 (NPQ10), and so on. Treatment of nail psoriasis should be individualized according to the number of involving nail, the affected site of nail and presence of skin and/or joint involvement. Generally, topical therapies are used for mild nail psoriasis, while biologic agents such as etanercept are considered for severe nail disease and refractory nail psoriasis. Even though the current literature has shown some support for the pathogenesis, clinical presentation, or therapies of nail psoriasis, systemic review of this multifaceted disease is still rare to date. We elaborate recent developments in nail psoriasis epidemiology, pathogenesis, anatomy, clinical manifestation, diagnosis, differential diagnosis, and therapies to raise better awareness of the complexity of nail psoriasis and the need for early diagnosis or intervention.

Three-Dimensional Structure Analysis of Mouse Nails using Synchrotron Radiation

Until now, studies on nail disease have been performed through microscopic diagnosis and microscopic computed tomography (micro-CT). However, these kinds of conventional methods have some limitations. Firstly, the microscopic method is considered the gold standard for medical diagnosis. However, due to the use of fluorescent materials, the sample is damaged and it takes a long time to get results. Secondly, while micro-CT is a non-invasive method to get inner structure images of the sample with high resolution, the penetration and spatial resolution are insufficient for studying the microstructures of the sample, such as the sponge bone and the muscle fibers. In contrast, synchrotron radiation (SR) X-ray imaging technology has the advantage of very vividly demonstrating the anatomic structure of the sample with high penetration, sensitivity, and resolution. In this study, we compared the optical microscopic method using hematoxylin and eosin (H&E) staining and SR imaging to analyze the nail tissue in a mouse model. The results showed that SR could depict the inner structures of a mouse nail without physical damage. Additionally, we could divide the important anatomical structures nail unit into three parts with three-dimensional images: the nail bed, nail matrix, and hyponychium. The images showed that SR could be used for analyzing nails by visualizing the relatively clear and medically semantic structures in a three-dimensional section. We expect that the results of this study will be applied to study nail diseases and pharmaceutical research on their treatment.

Diagnosis of Onychomycosis: From Conventional Techniques and Dermoscopy to Artificial Intelligence

Onychomycosis is a common fungal nail infection. Accurate diagnosis is critical as onychomycosis is transmissible between humans and impacts patients' quality of life. Combining clinical examination with mycological testing ensures accurate diagnosis. Conventional diagnostic techniques, including potassium hydroxide testing, fungal culture and histopathology of nail clippings, detect fungal species within nails. New diagnostic tools have been developed recently which either improve detection of onychomycosis clinically, including dermoscopy, reflectance confocal microscopy and artificial intelligence, or mycologically, such as molecular assays. Dermoscopy is cost-effective and non-invasive, allowing clinicians to discern microscopic features of onychomycosis and fungal melanonychia. Reflectance confocal microscopy enables clinicians to observe bright filamentous septate hyphae at near histologic resolution by the bedside. Artificial intelligence may prompt patients to seek further assessment for nails that are suspicious for onychomycosis. This review evaluates the current landscape of diagnostic techniques for onychomycosis.

Clinical Applications of In Vivo and Ex Vivo Confocal Microscopy

Confocal laser scanning microscopy (CLSM) has been introduced in clinical settings as a tool enabling a quasi-histologic view of a given tissue, without performing a biopsy. It has been applied to many fields of medicine mainly to the skin and to the analysis of skin cancers for both in vivo and ex vivo CLSM. In vivo CLSM involves reflectance mode, which is based on refractive index of cell structures serving as endogenous chromophores, reaching a depth of exploration of 200 μm. It has been proven to increase the diagnostic accuracy of skin cancers, both melanoma and non-melanoma. While histopathologic examination is the gold standard for diagnosis, in vivo CLSM alone and in addition to dermoscopy, contributes to the reduction of the number of excised lesions to exclude a melanoma, and to improve margin recognition in lentigo maligna, enabling tissue sparing for excisions. Ex vivo CLSM can be performed in reflectance and fluorescent mode. Fluorescence confocal microscopy is applied for “real-time” pathological examination of freshly excised specimens for diagnostic purposes and for the evaluation of margin clearance after excision in Mohs surgery. Further prospective interventional studies using CLSM might contribute to increase the knowledge about its application, reproducing real-life settings.

Ex vivo Confocal Laser Scanning Microscopy: A Potential New Diagnostic Imaging Tool in Onychomycosis Comparable With Gold Standard Techniques

Ex vivo confocal laser scanning microscopy (CLSM) is an innovative imaging tool that enables real-time examination of specimens and may be used in evaluating fungal infections. We aimed to assess the applicability of ex vivo CLSM in the diagnosis of onychomycosis by comparing results to those obtained by histopathology, potassium hydroxide (KOH) examination, and fungal culture. In this prospective study, 57 patients with the clinical diagnosis of distal nail fungal infection were examined and compared using all four of the above-mentioned diagnostic tools in terms of sensitivity, positive and negative predictive value. Ex vivo CLSM showed the highest sensitivity, followed by KOH examination, histopathology and fungal culture. Regarding positive and negative predictive values, ex vivo CLSM was superior and showed even higher sensitivity than the combined gold standard comprised of KOH examination, fungal culture or histopathology.

Morphometric Optical Imaging of Microporated Nail Tissue: An Investigation of Intermethod Agreement, Reliability, and Technical Limitations

BACKGROUND AND OBJECTIVES

While optical imaging is a useful technique to quantitate morphological differences and treatment effects, comparative investigations of the various techniques are lacking. This study aimed at evaluating intermethod agreement, reliability, and technical limitations of wide-field microscopy (WFM), reflectance confocal microscopy (RCM), and optical coherence tomography (OCT) for morphometry by assessing fractionally ablated nail tissue.

STUDY DESIGN/MATERIALS AND METHODS

Fifty healthy nail clippings were processed with a fractionated CO₂ -laser (20 mJ/microbeam, density 15%), measured with calipers, and imaged using WFM, OCT, and RCM. Images were assessed for nail plate thickness, micropore dimensions, degree of poration, and artifacts. Repeated measurements (2-5) were taken to evaluate method repeatability using Cronbach's α and coefficients of variation (CoV), and estimate the intermethod correlation through linear correlation assessment (Pearson correlation coefficient [PCC]), ranked correlation (Kendall's tau; tau-c), and intraclass correlation (Shrout-Fleiss reliability coefficient; ICC).

RESULTS

The repeatability varied substantially between methods and target measurements. The level of intermethod agreement for thickness measurements performed with calipers, WFM, and OCT was high (tau-c ≥ 0.7; ICC ≥ 0.8; PCC ≥ 0.9). RCM could only image 28 out of 50 samples due to its limited penetration depth. OCT demonstrated the highest repeatability of all imaging techniques (CoV 4-7%) and nail thickness showed the highest measurement reliability (α = 0.92). Micropore dimensions correlated strongest between OCT and RCM (tau-c/ICC/PCC ≥ 0.5). All modalities were prone to artifacts, which may have adversely affected measurement variation and intermethod agreement.

CONCLUSION

Intermethod agreement and reliability appear to be highly dependent on the specific modality and target measurement. To reap the benefits of each technique while mitigating their limitations, an integrated approach to optical imaging is recommended. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Ex vivo confocal microscopy: revolution in fast pathology in dermatology

Confocal microscopy with in vivo and ex vivo modalities has been used in the evaluation of skin cancer and other dermatological disorders. Recent developments in ex vivo confocal microscopy allow for faster pathology assessment with greater accuracy by the visualization of cellular and architectural details, similarly to standard pathology, in either paraffin-embedded or frozen samples. They include the possibility of multimodal confocal microscopy using different lasers and fusion images. New staining protocols including immunostaining, with no damage to conventional histopathology preparation, have been recently described in melanocytic tumours and inflammatory skin diseases. Digital staining with haematoxylin and eosin is also incorporated in the new devices. In this review the applications of ex vivo confocal microscopy will be presented with the description of the technique and the technology, clinical evidence in dermatology and other fields, and further applications.

Intraoperative onychoscopy and histopathological correlation of red lunula in nail lichen planus: a case series

The lunula is the white half-moon-shaped area located at the base of the fingernails and toenails, and is the only visible part of nail matrix. Red lunula can present as a complete form (the whole lunula is red), incomplete form (only the proximal lunula is red) or mottled form. Red lunula has been associated with a number of dermatological and systemic conditions. It is one of the less common manifestations of nail lichen planus (LP). However, the pathogenesis of the red lunula is not yet clear. We present a series of six patients with nail LP presenting with red lunula, and describe the findings of intraoperative onychoscopy and histopathology in an attempt to understand the pathogenesis underlying the condition.

In Vivo Reflectance Confocal Microscopy in General Dermatology: How to Choose the Right Indication

Reflectance confocal microscopy (RCM) is a high-resolution, noninvasive imaging technique being increasingly used as an aid to diagnosis in the dermatology setting. RCM is applied in the diagnosis of both melanoma and nonmelanoma skin tumors, but also in the interpretation and management of inflammatory skin diseases. Two different devices with different designs for specific indications are available in the market: a static and a handheld probe. Several clinical presentations of the lesion could affect the examination, such as the presence of ulceration or hyperkeratosis; moreover, the anatomical site can drive the probe selection as well as the effective indication to RCM examination. In this review article, indications for the use of RCM are described in detail with a schematic approach for practical purposes.

Emerging Optical Techniques for the Diagnosis of Onychomycosis

Onychomycosis is the most prevalent nail infection. Although it is not a life-threatening condition, it impacts the quality of life for many patients and often imposes a challenging diagnostic problem. The causative agents are dermatophytes, yeasts and non-dermatophytic moulds. Accurate and early diagnosis, including the identification of the causative species, is the key factor for rational therapy. Still, early diagnosis is not optimal as the current gold standard for the differentiation of the infectious agents is culture-based approaches. On the other hand, noninvasive optical technologies may enable differential diagnosis of nail pathologies including onychomycosis. When light penetrates and propagates along the nail tissue, it interacts in different ways with the components of either infected or healthy nail segments, providing a wealth of diagnostic information upon escaping the tissue. This review aims to assess alternative optical techniques for the rapid diagnosis of onychomycosis with a potential to monitor therapeutic response or even identify the fungal agent non-invasively and in real time in a clinical setting.

Clinical and Instrumental Objective Evidence of the Efficacy of a New Water-Based Nail-Strengthening Solution Containing Pistacia lentiscus and Hyaluronic Acid Applied for Up to 6 Months to Improve the Appearance of Weak, Brittle Nails

INTRODUCTION

Brittle nails are fragile or split nails; they affect 20% of the population and may be primary or secondary to different conditions. The aim of our studies was to evaluate the efficacy and tolerability of a new water-based nail-strengthening treatment containing hyaluronic acid and Pistacia lentiscus with daily application for a period of 1-3 months for one study (n = 30) and up to 6 months for a second study (n = 30).

METHODS

In total, we enrolled 60 patients of both sexes with brittle and weak nails due to primary or secondary causes and evaluated the efficacy of this new product using subjective and objective methods: clinical evaluation, assessment of photographs, onychoscopy evaluation, investigator and patient global assessment, dynamic optical coherence tomography (D-OCT) and reflectance confocal microscopy (RCM).

RESULTS

Studies subjects presented a statistically significant improvement in global assessment scale (GAS) scores at 14 days (GAS = 1.7 ± 0.6), 1 month (GAS = 1.4 ± 0.7) and at 3 months (GAS = 1±0.7) versus the GAS score obtained before treatment (1.9 ± 0.5) (p < 0.0001). From the Italian study at 6 months (n = 30) 76% of the patients had an improvement in their nail appearance. Reduction in nail plate roughness with improved nail resistance and decreased distal breakage were the most evident benefits, demonstrated on clinical and instrumental evaluations. No side effects were reported. All patients reported an improvement in nail appearance after using the product for 1 month, 3 months and 6 months, and had a positive opinion on the product.

CONCLUSIONS

This new product is an effective, safe, and easy-to-use option for topical treatment of brittle nails and primary nail fragility and an adjuvant therapy in secondary nail fragility. Moreover, its ease of application and cosmetic qualities allow good compliance.

FUNDING

ISDIN.

Ex Vivo Confocal Microscopy Using Fusion Mode and Digital Staining: Changing Paradigms in Histological Diagnosis

The ex vivo confocal microscope is an imaging system designed to analyze freshly excised tissue using two diode lasers with different wavelengths. The technique can dramatically reduce margin analysis times and offers a sensitivity of 88% and a specificity of 89% relative to histopathology. A new technology has recently been developed that produces images more quickly and with a higher resolution than before. By means of a fusion mode that combines simultaneously scanned fluorescence and reflectance images, it produces digitally stained images that simulate the effect of hematoxylin-eosin staining. Application of this new technology has opened the door to real-time tissue diagnostics.

Ex vivo confocal microscopy: an emerging technique in dermatology

This review aims to give an overview of the current available applications of ex vivo confocal microscopy (EVCM) in dermatology. EVCM is a relatively new imaging technique that allows microscopic examination of freshly excised unfixed tissue. It enables a rapid examination of the skin sample directly in the surgery room and thus represents an alternative to the intraoperative micrographic control of the surgical margins of cutaneous tumors by standard microscopic examination on cryopreserved sections during Mohs surgery. Although this technique has mainly been developed for the margin’s control of basal cell carcinoma, many other skin tumors have been studied, including melanoma. Use of EVCM is continuing to evolve, and many possible applications are under investigation, such as the study of nails and hair diseases and the diagnosis of skin infections.

[The role of reflectance confocal microscopy in the diagnosis of secondary syphilis of the vulva and anus: A first case report]

PATIENTS AND METHODS

Herein we report the case of an 18-year-old pregnant patient presenting with plantar and ano-genital lesions of syphilis, pharyngitis, erythematosus and scalynasolabial intertrigo and angular cheilitis.

REFLECTANCE CONFOCAL MICROSCOPY

In vivo reflectance confocal microscopy examination (Vivascope 3000^®; Caliber Inc, Rochester, NY, USA, distributed in France by Mavig, Munich) of ano-genital lesions enabled us to identify hyper-reflective elongated rods in the papillary dermis suggesting spirochetes. The diagnosis was confirmed by TPHA and VDRL as well as immunohistological examination.

COMMENTS

We identified for the first time rod shaped structures in ano-genital lesions of secondary syphilis, regularly alternating hyper-reflective and non-reflective areas corresponding to helix-shaped treponemes visualized by darkfield microscopy, which may not be confused with other cell structures.

Onychomycosis: A Review

Onychomycosis is the most common nail infective disorder. It is caused mainly by anthropophilic dermatophytes, in particular by Trichophyton rubrum and T. mentagrophytes var. interdigitale. Yeasts, like Candida albicans and C. parapsilosis, and molds, like Aspergillus spp., represent the second cause of onychomycosis. The clinical suspect of onychomycosis should be confirmed my mycology. Onychoscopy is a new method that can help the physician, as in onychomycosis, it shows a typical fringed proximal margin. Treatment is chosen depending on the modality of nail invasion, fungus species and the number of affected nails. Oral treatments are often limited by drug interactions, while topical antifungal lacquers have less efficacy. A combination of both oral and systemic treatment is often the best choice.